Objective: To compare growth factor receptor expression in papilla of Vater cancer and pancreatic cancer.
Summary background data: Cancer of the papilla of Vater has a much better prognosis than pancreatic cancer. Earlier symptoms may result in earlier diagnosis, but different biologic growth behaviors and genetic alterations might also be explanations.
Patients and methods: Surgical specimens from papilla of Vater cancers (24 patients) and pancreatic cancers (80 patients), normal papilla of Vater tissues (20 patients), and normal pancreatic tissues (24 patients) were frozen and fixed. The authors compared the expression of the epidermal growth factor receptor (EGFR) and c-erbB2 and c-erbB3 by Northern blot, in situ hybridization, and immunohistochemistry.
Results: In papilla of Vater cancer, Northern blots showed comparable EGFR and c-erbB2 mRNA expression but significantly lower c-erbB3 mRNA levels than in normal papilla. In pancreatic cancer, mRNA expression was enhanced compared with normal controls for EGFR (4-fold), c-erbB2 (2.5-fold), and c-erbB3 (5.2-fold). In situ hybridization confirmed this and showed mRNA expression only in cancer cells. EGFR immunohistochemical staining scores were comparable in papilla of Vater cancer (1.17 +/- 0.22) and normal papilla (1.42 +/- 0.25). Staining scores for c-erbB2 (2.72 +/- 0.40 vs. 3.89 +/- 0.37) and c-erbB3 (2.78 +/- 0.35 vs. 3.89 +/- 0.53) were slightly lower than controls in papilla of Vater cancer. In pancreatic cancer, immunostaining scores for EGFR, c-erbB2, and c-erbB3 were significantly higher than controls.
Conclusion: Members of the EGFR family show similar or lower expression in papilla of Vater cancer than in normal controls. In pancreatic cancer, these receptors are upregulated. This supports the hypothesis that papilla of Vater cancer and pancreatic cancer have biologic differences that may contribute to the different growth of these tumors.